The invention relates to a dual-stage, flow-through apparatus and method for simulating diagenesis. It further relates to a dual-stage, flow-through apparatus and method which has been designed and built to develop more accurate diagenetic models. The dual-stage, flow-through design simulates temperatures, lithostatic and hydrostatic pressures, mineralology, fluid flow and chemistry of subsurface geologic environments.
As known sources of oil, natural gas and minerals become depleted, it is essential that these resources be replaced as efficiently and economically as possible. One means of increasing production of resources is to prepare a diagenetic history of a given rock formation prior to drilling or mining so as to determine whether that formation was subject to conditions conducive to the formation of oil, natural gas or minerals.
Diagenesis includes all processes that convert sediments to rocks between the time of deposition and the onset of thermal metamorphism. Diagenetic models are used in frontier basins to predict the existence of hydrocarbons and minerals, the location of reservoirs, the types of porosity present, the occurrence of permeability-reducing factors and the location of diagenetic seals. The potential accumulation of hydrocarbons and minerals is influenced by the diagenetic history of the rock sample.
The exploration significance of the dual-stage, flow-through apparatus lies in its potential to develop more accurate diagenetic models. The apparatus is an intermediate stage between theoretical diagenetic models and actual in-situ geological environments. Its capabilities allow physical simulation of a theoretical model. It is the dual-stage, flow-through nature of the apparatus which allows simulation of diagenesis in natural systems.
As sediments are buried, heated and compacted, fluids are expelled. The chemistry of fluids are modified by water-rock interaction. The corrosive nature of aqueous fluids causes chemical alteration of both rocks and fluids. As the fluids move, they come into contact with other minerals at varying temperatures and pressures. Although the natures of the fluids are not known with accuracy, the successive stages of the experimental apparatus would allow one to mimic this process by the natural adjustment of fluid chemistry in successive stages. By duplicating downhole temperatures, pressures, fluid chemistries, mineralogies and flow regimes through compacting basins, direct simulation of a proposed diagenetic model is possible. A dual-stage, flow-through apparatus would allow the geologist to verify his diagenetic model.
A more accurate diagenetic model would help the geologist optimize drilling and mining opportunities in a given area of study.
It is thus an object of the invention to simulate diagenesis. It is a further object to utilize a dual-stage, flow-through apparatus to develop accurate diagenetic models.
Other objects, aspects and advantages of the invention will be apparent from the specification, drawings and appended claims to the invention.